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arXiv · 1304.6674

Focusing polychromatic light through strongly scattering media

Hari P. Paudel·Chris Stockbridge·Jerome Mertz·Thomas Bifano
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Abstract

We demonstrate feedback-optimized focusing of spatially coherent polychromatic light after transmission through strongly scattering media, and describe the relationship between optimized focus intensity and initial far-field speckle contrast. Optimization is performed using a MEMS spatial light modulator with camera-based or spectrometer-based feedback. We observe that the spectral bandwidth of the optimized focus depends on characteristics of the feedback signal. We interpret this dependence as a modification in the number of spectral modes transmitted by the sample, and introduce a simple model for polychromatic focus enhancement that is corroborated by experiment with calibrated samples.

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Hari P. Paudel, Chris Stockbridge, Jerome Mertz, Thomas Bifano. 2013-04-24. Focusing polychromatic light through strongly scattering media. https://doi.org/10.1364/oe.21.017299

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